/*
* INSANE - Interactive Structural Analysis Environment
*
* Copyright (C) 2003-2005
* Universidade Federal de Minas Gerais
* Escola de Engenharia
* Departamento de Engenharia de Estruturas
* 
* Author's email :    insane@dees.ufmg.br
* Author's website :  http://www.dees.ufmg.br/insane
* 
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or any later version.
* 
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
* 
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/
package br.ufmg.dees.insane.shape;

import br.ufmg.dees.insane.util.IMatrix;
import br.ufmg.dees.insane.util.IVector;

/**
*A class representing a linear shape in one dimension and cartesian coordinates.
*
*@author Fonseca, Flavio & Pitangueira, Roque
*@version 1.0
*@since September 2003
*@see model.discrete.element.FrameElement
*/

public class Linear1DCart extends Shape1DCart {
	
	private static final long serialVersionUID = 1L;
	
	/** Constructs a Linear1DCart shape.*/
	public Linear1DCart() {
	}
	
	/* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.Shape#getShapeFunction
     */
	public IVector getShapeFunction(double[] g, IMatrix cN) {
		double length = cN.getElement(0,0) - cN.getElement(1,0);
		IVector n = new IVector(2);
		n.setElement(0, 1-(g[0] / length));
		n.setElement(1, g[0] / length);
		return (n);
	}
	
	/* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.Shape#getDerivedShapeFunction
     */
	public IMatrix getDerivedShapeFunction(double[] g, IMatrix cN) {
		double length = cN.getElement(0,0) - cN.getElement(1,0);
		IMatrix n = new IMatrix(2, 1);
		n.setElement(0, 0, -1/length);
		n.setElement(1, 0, 1/length);
		return (n);
	}
	

	/* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.Shape#getSecondDerivedShapeFunction
     */
    public IMatrix getSecondDerivedShapeFunction(double[] g, IMatrix cN) {
    	IMatrix n = new IMatrix(2, 1);
        n.setElement(0, 0, 0);
        n.setElement(1, 0, 0);
        return (n);
    }
    
    /* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.Shape#getThirdDerivedShapeFunction
     */
    public IMatrix getThirdDerivedShapeFunction(double[] g, IMatrix cN) {
    	IMatrix n = new IMatrix(2, 1);
        n.setElement(0, 0, 0);
        n.setElement(1, 0, 0);
        return (n);
    }
    
    /* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.ShapeCart#getIntegratedShapeFunction
     */
	public IVector getIntegratedShapeFunction(double[] a, double[] b, IMatrix cN) {
		double l = cN.getElement(0,0) - cN.getElement(1,0);
		double x1 = a[0];
		double x2 = b[0];
		IVector n = new IVector(2);
		double n0 = (x2 - x2*x2/(2*l)) - (x1 - x1*x1/(2*l));
		double n1 = (x2*x2/(2*l)) - (x1*x1/(2*l));
		n.setElement(0, n0);
		n.setElement(1, n1);
		return (n);
	}
	
	/* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.ShapeCart#getIntegratedShapeFunctionTimesX
     */
	public IVector getIntegratedShapeFunctionTimesX(double[] a, double[] b, IMatrix cN) {
		double l = cN.getElement(0,0) - cN.getElement(1,0);
		double x1 = a[0];
		double x2 = b[0];
		IVector n = new IVector(2);
		double n0 = (x2*x2/2 - x2*x2*x2/(3*l)) - (x1*x1/2 - x1*x1*x1/(3*l));
		double n1 = (x2*x2*x2/(3*l)) - (x1*x1*x1/(3*l));
		n.setElement(0, n0);
		n.setElement(1, n1);
		return (n);
	}
	
    /* (non-Javadoc)
     * @see br.ufmg.dees.insane.Shape.Shape#getType
     */
    public String getType() {
		return "Linear1DCart";
	}

}
